PA R TURIENT A POPLEXY.—PA R TURIENT COLLAPSE. 6 7 1 



quicker and more continuous the uterus contractions, the more consider- 

 able is this flow of blood. Attention may casually be directed, to the fact, 

 that the after-pains are much more severe and continuous after a speedy 

 parturition, than after a tardy one. The blood forced back generally 

 finds its normal outlet by the udder and skin ; and by watching every nor- 

 mal parturition one can observe the acute swelling of the udder, which swel- 

 ling varies in proportion to the number and violence of the pains. By this 

 outflow into the udder and skin, and by which a collateral fluxion is es- 

 tablished, the accumulation of blood already alluded to, which would be 

 followed by aortic pressure,* is got rid of without detriment to the ani- 

 mal. In cases, however, where this stoppage is sudden and violent — as 

 happens after a chill to the surface of the body — the aortic pressure 

 must undoubtedly be considerably increased. 



One consequence of the increased pressure — always easily observable 

 after a little time, as will be shown presently — must, among others, be 

 congestion of the brain. But the soft brain-tissue can only offer a slight 

 opposition to the distention of the vessels ; consequentl}^, sudden effu- 

 sion and, as a result, brain oedema, ensues. This brain oedema, on its 

 part, causes contraction of the vessels and, in this way, arterial anaemia. 

 Tlie whole process, which can be followed step by step, is greatly aided 

 by {a) the heart's hyperplasia, {h) the increased flow of blood, and (<r) 

 the hydraemia which exists in pregnant animals. After parturition, the 

 heart does not at once resume its normal size ; it remains for some time 

 in a hypertrophied state. In fact, it seems as if the heart, in good milk- 

 ing Cows, follows the same law as increased circulation in the swollen 

 udder, and is much more enlarged than is the case with inferior milking 

 animals. The result of increased power of the heart is increased action. 

 The blood, which has been largely increased in a pregnant animal, does 

 not at once return to its normal quantity after parturition, but materially 

 aids in producing congestion, 



■ The remarkable fact always, however, holds true, that animals which 

 are in good condition without being fattened up, and those in which 

 the circulation is healthy, are particularly susceptible to calf-fever. An 

 animal which has calved, is like one into whose circulation a certain 

 quantity of blood has been transfused. This superabundance of blood 

 does not quickly disappear from the body; it takes, so to say, the place 

 of a new organ. In animals which have just brought forth, the milk 

 secretion expends this blood. Hydraemia is common to them all. Doubt- 

 less, the dilution of blood in pregnant animals is, as a rule, over-estimated. 

 There are, however, many cases of albuminous urine among Cows for 

 some weeks before parturition. Hydraemia is the natural result of this 

 condition of the urine, if it be of long standing. The watery condition of 

 the blood tends materially to brain oedema, if, indeed, this be not really 

 the actual consequence of such a condition. Particular inquiries furnish 

 statistical information as to the number of cases of calf-fever accompanied 

 or unaccompanied by albuminous urine. 



It is necessary, however, to append a consideration of a teleological 

 character. The act of parturition is naturally accompanied by great irri- 

 tability of the sensory nerves, and with much pain; whilst all other ope- 

 rations in animals, which have as their object the preservation of the 

 creature or species — such as appeasing hunger, slaking thirst, etc. — are 



* It must be remembered that blood stasis and undue distention of vessels, is not always due to blood- 

 pressure. Altered innervation of the walls of the vessels themselves can bring this about. 



